What I said already assumes that you delete the all instances of that content when you find out it's bad. FB already does this. Problem is, that people see cont

What I said already assumes that you delete the all instances of that content when you find out it's bad. FB already does this. Problem is, that people see content before it is taken down. And once it's taken down, bad actors stop uploading it, and slightly change it (enough to make it pass existing upload filter).